Optical links provide high data transmission rates at low power, and thus present a viable solution for replacing ordinary copper interconnects between integrated circuits. Optical reception is based on capturing, using a photodiode, a light signal that is generally encoded in a digital fashion, and which may have a power level as low as 10 μW. The photosensitive device for example generates a small current that is transformed by the optical receiver into a digital voltage signal.
The power level of the received optical signal may vary in time, and therefore, in order to correctly receive the transmitted signal, calibration of the optical receiver is generally required. However, a problem with existing solutions for calibrating the optical receiver is that they tend to be complex and consuming in chip area and energy consumption, slow to converge to an appropriate level and/or overly influenced by the transmitted data signal.
United States patent application published under the number US2013/0108280 describes an optical receiver comprising a threshold detection circuit.
United States patent application published under the number US2014/0029958 describes a detecting apparatus including a threshold detection circuit that detects, by a switchable time constant, a threshold of a level of an input optical burst signal.